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1 | /* |
2 | * Functions related to generic helpers functions |
3 | */ |
4 | #include <linux/kernel.h> |
5 | #include <linux/module.h> |
6 | #include <linux/bio.h> |
7 | #include <linux/blkdev.h> |
8 | #include <linux/scatterlist.h> |
9 | |
10 | #include "blk.h" |
11 | |
12 | struct bio_batch { |
13 | atomic_t done; |
14 | unsigned long flags; |
15 | struct completion *wait; |
16 | }; |
17 | |
18 | static void bio_batch_end_io(struct bio *bio, int err) |
19 | { |
20 | struct bio_batch *bb = bio->bi_private; |
21 | |
22 | if (err && (err != -EOPNOTSUPP)) |
23 | clear_bit(BIO_UPTODATE, &bb->flags); |
24 | if (atomic_dec_and_test(&bb->done)) |
25 | complete(bb->wait); |
26 | bio_put(bio); |
27 | } |
28 | |
29 | /** |
30 | * blkdev_issue_discard - queue a discard |
31 | * @bdev: blockdev to issue discard for |
32 | * @sector: start sector |
33 | * @nr_sects: number of sectors to discard |
34 | * @gfp_mask: memory allocation flags (for bio_alloc) |
35 | * @flags: BLKDEV_IFL_* flags to control behaviour |
36 | * |
37 | * Description: |
38 | * Issue a discard request for the sectors in question. |
39 | */ |
40 | int blkdev_issue_discard(struct block_device *bdev, sector_t sector, |
41 | sector_t nr_sects, gfp_t gfp_mask, unsigned long flags) |
42 | { |
43 | DECLARE_COMPLETION_ONSTACK(wait); |
44 | struct request_queue *q = bdev_get_queue(bdev); |
45 | int type = REQ_WRITE | REQ_DISCARD; |
46 | unsigned int max_discard_sectors, granularity; |
47 | int alignment; |
48 | struct bio_batch bb; |
49 | struct bio *bio; |
50 | int ret = 0; |
51 | struct blk_plug plug; |
52 | |
53 | if (!q) |
54 | return -ENXIO; |
55 | |
56 | if (!blk_queue_discard(q)) |
57 | return -EOPNOTSUPP; |
58 | |
59 | /* Zero-sector (unknown) and one-sector granularities are the same. */ |
60 | granularity = max(q->limits.discard_granularity >> 9, 1U); |
61 | alignment = (bdev_discard_alignment(bdev) >> 9) % granularity; |
62 | |
63 | /* |
64 | * Ensure that max_discard_sectors is of the proper |
65 | * granularity, so that requests stay aligned after a split. |
66 | */ |
67 | max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9); |
68 | max_discard_sectors -= max_discard_sectors % granularity; |
69 | if (unlikely(!max_discard_sectors)) { |
70 | /* Avoid infinite loop below. Being cautious never hurts. */ |
71 | return -EOPNOTSUPP; |
72 | } |
73 | |
74 | if (flags & BLKDEV_DISCARD_SECURE) { |
75 | if (!blk_queue_secdiscard(q)) |
76 | return -EOPNOTSUPP; |
77 | type |= REQ_SECURE; |
78 | } |
79 | |
80 | atomic_set(&bb.done, 1); |
81 | bb.flags = 1 << BIO_UPTODATE; |
82 | bb.wait = &wait; |
83 | |
84 | blk_start_plug(&plug); |
85 | while (nr_sects) { |
86 | unsigned int req_sects; |
87 | sector_t end_sect, tmp; |
88 | |
89 | bio = bio_alloc(gfp_mask, 1); |
90 | if (!bio) { |
91 | ret = -ENOMEM; |
92 | break; |
93 | } |
94 | |
95 | req_sects = min_t(sector_t, nr_sects, max_discard_sectors); |
96 | |
97 | /* |
98 | * If splitting a request, and the next starting sector would be |
99 | * misaligned, stop the discard at the previous aligned sector. |
100 | */ |
101 | end_sect = sector + req_sects; |
102 | tmp = end_sect; |
103 | if (req_sects < nr_sects && |
104 | sector_div(tmp, granularity) != alignment) { |
105 | end_sect = end_sect - alignment; |
106 | sector_div(end_sect, granularity); |
107 | end_sect = end_sect * granularity + alignment; |
108 | req_sects = end_sect - sector; |
109 | } |
110 | |
111 | bio->bi_iter.bi_sector = sector; |
112 | bio->bi_end_io = bio_batch_end_io; |
113 | bio->bi_bdev = bdev; |
114 | bio->bi_private = &bb; |
115 | |
116 | bio->bi_iter.bi_size = req_sects << 9; |
117 | nr_sects -= req_sects; |
118 | sector = end_sect; |
119 | |
120 | atomic_inc(&bb.done); |
121 | submit_bio(type, bio); |
122 | |
123 | /* |
124 | * We can loop for a long time in here, if someone does |
125 | * full device discards (like mkfs). Be nice and allow |
126 | * us to schedule out to avoid softlocking if preempt |
127 | * is disabled. |
128 | */ |
129 | cond_resched(); |
130 | } |
131 | blk_finish_plug(&plug); |
132 | |
133 | /* Wait for bios in-flight */ |
134 | if (!atomic_dec_and_test(&bb.done)) |
135 | wait_for_completion_io(&wait); |
136 | |
137 | if (!test_bit(BIO_UPTODATE, &bb.flags)) |
138 | ret = -EIO; |
139 | |
140 | return ret; |
141 | } |
142 | EXPORT_SYMBOL(blkdev_issue_discard); |
143 | |
144 | /** |
145 | * blkdev_issue_write_same - queue a write same operation |
146 | * @bdev: target blockdev |
147 | * @sector: start sector |
148 | * @nr_sects: number of sectors to write |
149 | * @gfp_mask: memory allocation flags (for bio_alloc) |
150 | * @page: page containing data to write |
151 | * |
152 | * Description: |
153 | * Issue a write same request for the sectors in question. |
154 | */ |
155 | int blkdev_issue_write_same(struct block_device *bdev, sector_t sector, |
156 | sector_t nr_sects, gfp_t gfp_mask, |
157 | struct page *page) |
158 | { |
159 | DECLARE_COMPLETION_ONSTACK(wait); |
160 | struct request_queue *q = bdev_get_queue(bdev); |
161 | unsigned int max_write_same_sectors; |
162 | struct bio_batch bb; |
163 | struct bio *bio; |
164 | int ret = 0; |
165 | |
166 | if (!q) |
167 | return -ENXIO; |
168 | |
169 | max_write_same_sectors = q->limits.max_write_same_sectors; |
170 | |
171 | if (max_write_same_sectors == 0) |
172 | return -EOPNOTSUPP; |
173 | |
174 | atomic_set(&bb.done, 1); |
175 | bb.flags = 1 << BIO_UPTODATE; |
176 | bb.wait = &wait; |
177 | |
178 | while (nr_sects) { |
179 | bio = bio_alloc(gfp_mask, 1); |
180 | if (!bio) { |
181 | ret = -ENOMEM; |
182 | break; |
183 | } |
184 | |
185 | bio->bi_iter.bi_sector = sector; |
186 | bio->bi_end_io = bio_batch_end_io; |
187 | bio->bi_bdev = bdev; |
188 | bio->bi_private = &bb; |
189 | bio->bi_vcnt = 1; |
190 | bio->bi_io_vec->bv_page = page; |
191 | bio->bi_io_vec->bv_offset = 0; |
192 | bio->bi_io_vec->bv_len = bdev_logical_block_size(bdev); |
193 | |
194 | if (nr_sects > max_write_same_sectors) { |
195 | bio->bi_iter.bi_size = max_write_same_sectors << 9; |
196 | nr_sects -= max_write_same_sectors; |
197 | sector += max_write_same_sectors; |
198 | } else { |
199 | bio->bi_iter.bi_size = nr_sects << 9; |
200 | nr_sects = 0; |
201 | } |
202 | |
203 | atomic_inc(&bb.done); |
204 | submit_bio(REQ_WRITE | REQ_WRITE_SAME, bio); |
205 | } |
206 | |
207 | /* Wait for bios in-flight */ |
208 | if (!atomic_dec_and_test(&bb.done)) |
209 | wait_for_completion_io(&wait); |
210 | |
211 | if (!test_bit(BIO_UPTODATE, &bb.flags)) |
212 | ret = -ENOTSUPP; |
213 | |
214 | return ret; |
215 | } |
216 | EXPORT_SYMBOL(blkdev_issue_write_same); |
217 | |
218 | /** |
219 | * blkdev_issue_zeroout - generate number of zero filed write bios |
220 | * @bdev: blockdev to issue |
221 | * @sector: start sector |
222 | * @nr_sects: number of sectors to write |
223 | * @gfp_mask: memory allocation flags (for bio_alloc) |
224 | * |
225 | * Description: |
226 | * Generate and issue number of bios with zerofiled pages. |
227 | */ |
228 | |
229 | static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, |
230 | sector_t nr_sects, gfp_t gfp_mask) |
231 | { |
232 | int ret; |
233 | struct bio *bio; |
234 | struct bio_batch bb; |
235 | unsigned int sz; |
236 | DECLARE_COMPLETION_ONSTACK(wait); |
237 | |
238 | atomic_set(&bb.done, 1); |
239 | bb.flags = 1 << BIO_UPTODATE; |
240 | bb.wait = &wait; |
241 | |
242 | ret = 0; |
243 | while (nr_sects != 0) { |
244 | bio = bio_alloc(gfp_mask, |
245 | min(nr_sects, (sector_t)BIO_MAX_PAGES)); |
246 | if (!bio) { |
247 | ret = -ENOMEM; |
248 | break; |
249 | } |
250 | |
251 | bio->bi_iter.bi_sector = sector; |
252 | bio->bi_bdev = bdev; |
253 | bio->bi_end_io = bio_batch_end_io; |
254 | bio->bi_private = &bb; |
255 | |
256 | while (nr_sects != 0) { |
257 | sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects); |
258 | ret = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0); |
259 | nr_sects -= ret >> 9; |
260 | sector += ret >> 9; |
261 | if (ret < (sz << 9)) |
262 | break; |
263 | } |
264 | ret = 0; |
265 | atomic_inc(&bb.done); |
266 | submit_bio(WRITE, bio); |
267 | } |
268 | |
269 | /* Wait for bios in-flight */ |
270 | if (!atomic_dec_and_test(&bb.done)) |
271 | wait_for_completion_io(&wait); |
272 | |
273 | if (!test_bit(BIO_UPTODATE, &bb.flags)) |
274 | /* One of bios in the batch was completed with error.*/ |
275 | ret = -EIO; |
276 | |
277 | return ret; |
278 | } |
279 | |
280 | /** |
281 | * blkdev_issue_zeroout - zero-fill a block range |
282 | * @bdev: blockdev to write |
283 | * @sector: start sector |
284 | * @nr_sects: number of sectors to write |
285 | * @gfp_mask: memory allocation flags (for bio_alloc) |
286 | * |
287 | * Description: |
288 | * Generate and issue number of bios with zerofiled pages. |
289 | */ |
290 | |
291 | int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, |
292 | sector_t nr_sects, gfp_t gfp_mask) |
293 | { |
294 | if (bdev_write_same(bdev)) { |
295 | unsigned char bdn[BDEVNAME_SIZE]; |
296 | |
297 | if (!blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask, |
298 | ZERO_PAGE(0))) |
299 | return 0; |
300 | |
301 | bdevname(bdev, bdn); |
302 | pr_err("%s: WRITE SAME failed. Manually zeroing.\n", bdn); |
303 | } |
304 | |
305 | return __blkdev_issue_zeroout(bdev, sector, nr_sects, gfp_mask); |
306 | } |
307 | EXPORT_SYMBOL(blkdev_issue_zeroout); |
308 |
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